Abstract: A filter device that removes a noise current generated by an inverter includes a first filter capacitor that is provided in parallel to a direct-current unit of the inverter, a first filter reactor that is provided between a high-potential side of the first filter capacitor and an overhead line that is a power supply source of direct-current power, and a series circuit unit in which a fuse serving as a circuit disconnecting unit that is disconnected when a current larger than a rated current flows therein, a second filter reactor serving as an inductance element, and a second filter capacitor serving as a capacitance element are connected in series, where one end of the series circuit unit is connected to a low-potential side of the first filter capacitor and one end of the first filter reactor is connected to the series circuit unit.

Abstract: An electrical power converter includes: AC voltage terminals U, V, and W; DC voltage terminals P and N; a converter cell series unit composed of one or more converter cells connected in series between the AC voltage terminals U, V, and W and the DC voltage terminals P and N, each converter cell including a semiconductor element and a capacitor; and a first inductance connected in series to the converter cell series unit, between, of the DC voltage terminals P and N, a DC voltage terminal at the lowest potential with respect to the ground, and the AC voltage terminals U, V, and W.

Abstract: A power conversion device includes transformers provided with primary windings connected to input terminals and secondary windings including pluralities of single-phase open windings that are insulated to each other; a plurality of converter cells connected to the secondary windings of the transformers; and a control circuit for controlling ON/OFF of switching elements. The converter cells are each include a converter and the inverter that are provided with the switching elements, in which their input ends are connected to the respective single-phase open windings, so that the input ends are connected in mutually parallel fashion, through the transformers, to the input terminal of each phase, and in which their output ends are connected in mutually serial fashion to an output terminal of each phase, to thereby perform three or more-level power conversion.

Abstract: A power conversion device including: an energy storage unit which receives and stores voltage of a self-power-feeding device; and a bypass unit drive device which, when voltage of the self-power-feeding device becomes smaller than a predetermined lower limit value, causes a bypass unit to perform short-circuiting operation by power stored in the energy storage unit. Thus, by appropriately setting the above voltage lower limit value as a threshold value for the short-circuiting operation, it becomes possible to swiftly and reliably perform short-circuiting protection operation even if a cell converter has failed, thus it is possible to always safely continue the operation of the power conversion device.

Abstract: An electric power conversion device includes a plurality of cell converters connected in cascade and including main circuits, drive circuits, and self-feeding devices for supplying power to the drive circuits by being supplied with power from the main circuits. The drive circuit is supplied with power via a first feed line from the self-feeding device in the corresponding cell converter, and supplied with power from the self-feeding device in another cell converter via a second feed line on which an insulation input/output circuit is provided. When the self-feeding device is abnormal, the drive circuit is supplied with power from the self-feeding device in the other cell converter, whereby the electric power conversion device continuously provides a desired output.

Abstract: A power conversion device in which a plurality of converter cells are connected in series with one another. The converter cells each include two or more semiconductor devices, an energy storage element and a bypass element including a constituent element for setting the bypass element to be close-circuited by detecting abnormality of a converter cell, and including a constituent element for controlling, among the semiconductor devices, a semiconductor device connected in parallel with the bypass element to set in a turn-on state, at the same time when the bypass element is set close-circuited or in advance of its close circuit.

Abstract: Phase arms each having one or more converter cells connected in series are provided between AC terminals U, V, W and DC terminals P and N. At least one of the converter cells is a first converter cell in which an energy accumulating element, a first leg, and a second leg are connected in parallel. The first leg has upper and lower arms both having semiconductor switching elements. The second leg has upper and lower arms one of which has a diode and the other one of which has a semiconductor switching element.

Abstract: An electric power conversion device includes a plurality of cell converters connected in cascade and including main circuits, drive circuits, and self-feeding devices for supplying power to the drive circuits by being supplied with power from the main circuits. The drive circuit is supplied with power via a first feed line from the self-feeding device in the corresponding cell converter, and supplied with power from the self-feeding device in another cell converter via a second feed line on which an insulation input/output circuit is provided. When the self-feeding device is abnormal, the drive circuit is supplied with power from the self-feeding device in the other cell converter, whereby the electric power conversion device continuously provides a desired output.

Abstract: A power conversion device includes an inverter that drives a motor; a fin that cools down the inverter; a first core including a through hole that allows passage of a positive side conductor that connects a power supply system and the inverter and a negative side conductor that grounds the inverter; a ground conductor that grounds the fin; a ground conductor that grounds a motor yoke via a capacitor; and a ground conductor including one end that is connected to the negative side conductor or the ground conductor and the other end that is grounded.

Abstract: A cell block including a plurality of cell converters connected in cascade and each including switching elements and a capacitor is provided. The cell block includes external connection terminals for connecting to another cell block in cascade, and a bypass circuit is connected to the external connection terminals.

Abstract: A filter device that removes a noise current generated by an inverter includes a first filter capacitor that is provided in parallel to a direct-current unit of the inverter, a first filter reactor that is provided between a high-potential side of the first filter capacitor and an overhead line that is a power supply source of direct-current power, and a series circuit unit in which a fuse serving as a circuit disconnecting unit that is disconnected when a current larger than a rated current flows therein, a second filter reactor serving as an inductance element, and a second filter capacitor serving as a capacitance element are connected in series, where one end of the series circuit unit is connected to a low-potential side of the first filter capacitor and one end of the first filter reactor is connected to the series circuit unit.

Abstract: A power conversion device includes transformers provided with primary windings connected to input terminals and secondary windings including pluralities of single-phase open windings that are insulated to each other; a plurality of converter cells connected to the secondary windings of the transformers; and a control circuit for controlling ON/OFF of switching elements. The converter cells are each include a converter and the inverter that are provided with the switching elements, in which their input ends are connected to the respective single-phase open windings, so that the input ends are connected in mutually parallel fashion, through the transformers, to the input terminal of each phase, and in which their output ends are connected in mutually serial fashion to an output terminal of each phase, to thereby perform three or more-level power conversion.

Abstract: An electrical power converter includes: AC voltage terminals U, V, and W; DC voltage terminals P and N; a converter cell series unit composed of one or more converter cells connected in series between the AC voltage terminals U, V, and W and the DC voltage terminals P and N, each converter cell including a semiconductor element and a capacitor; and a first inductance connected in series to the converter cell series unit, between, of the DC voltage terminals P and N, a DC voltage terminal at the lowest potential with respect to the ground, and the AC voltage terminals U, V, and W.

Abstract: A leg includes: two semiconductor device groups connected in series and a division current is generated in a current which flows in the semiconductor device group between elements in the semiconductor device groups, a current sensor which detects a current which flows in the semiconductor device group, a voltage command generation unit which calculates a voltage command value to be outputted, a voltage drop calculating unit which calculates a voltage drop of the semiconductor device group by using a current value which is detected by the current sensor and voltage drop characteristics including a division characteristic of the semiconductor device group, and a switching control unit which corrects a voltage command value which is generated by the voltage command generation unit by using the voltage drop which is calculated so as to control ON/OFF of the switching element.

Abstract: A power conversion device includes an inverter that drives a motor; a fin that cools down the inverter; a first core including a through hole that allows passage of a positive side conductor that connects a power supply system and the inverter and a negative side conductor that grounds the inverter; a ground conductor that grounds the fin; a ground conductor that grounds a motor yoke via a capacitor; and a ground conductor including one end that is connected to the negative side conductor or the ground conductor and the other end that is grounded.

Abstract: A leg includes: two semiconductor device groups connected in series and a division current is generated in a current which flows in the semiconductor device group between elements in the semiconductor device groups, a current sensor which detects a current which flows in the semiconductor device group, a voltage command generation unit which calculates a voltage command value to be outputted, a voltage drop calculating unit which calculates a voltage drop of the semiconductor device group by using a current value which is detected by the current sensor and voltage drop characteristics including a division characteristic of the semiconductor device group, and a switching control unit which corrects a voltage command value which is generated by the voltage command generation unit by using the voltage drop which is calculated so as to control ON/OFF of the switching element.

Abstract: A power converting apparatus includes three sets of half-bridge inverters connected between output terminals of a solar battery, each of the half-bridge inverters including two series-connected switching devices, single-phase inverters connected to individual AC output lines of the bridge inverters, and two series-connected capacitors dividing a voltage of the solar battery, wherein output terminals of the single-phase inverters are connected to individual phases of a three-phase power system. Each of the half-bridge inverters is operated to output one pulse per half cycle, each of the single-phase inverters is controlled by PWM control operation to make up for a voltage insufficiency from the system voltage, and sums of outputs of the half-bridge inverters and the single-phase inverters are output to the power system.

Abstract: A three-phase inverter circuit including a DC portion including capacitors connected between output terminals of a solar battery and single-phase inverters connected in series with AC output lines of the three-phase inverter circuit that together constitute an inverter section, the inverter section being connected to a three-phase power system. The three-phase inverter circuit outputs a reverse-polarity voltage pulse during a period within each of basic voltage pulses of which pulsewidth corresponds to a half cycle every half cycle of a system voltage. A power burden born by the individual single-phase inverters in each half cycle is made approximately zero and the individual single-phase inverters make a correction for subtracting a common voltage from target output voltages of individual phases during the period when the reverse-polarity voltage pulse is generated.

Abstract: A power converting apparatus is provided with three sets of half-bridge inverters (4a-4c) connected between output terminals of a solar battery (1), each of the half-bridge inverters (4a-4c) including two series-connected switching devices, single-phase inverters (5a-5c) connected to individual AC output lines of the bridge inverters (4a-4c), and two series-connected capacitors (6a, 6b) for dividing a voltage of the solar battery (1), wherein output terminals of the single-phase inverters (5a-5c) are connected to individual phases of a three-phase power system (2). Each of the half-bridge inverters (4a-4c) is operated to output one pulse per half cycle, each of the single-phase inverters (5a-5c) is controlled by PWM control operation to make up for a voltage insufficiency from the system voltage, and sums of outputs of the half-bridge inverters (4a-4c) and the single-phase inverters (5a-5c) are output to the power system (2).

Abstract: A three-phase inverter circuit (4) of which DC portion is smoothing capacitors (3) connected between output terminals of a solar battery (1) and single-phase inverters (5a-5c) connected in series with AC output lines of the three-phase inverter circuit (4) together constitute an inverter section, and this inverter section is connected to a three-phase power system (2). The three-phase inverter circuit (4) outputs a reverse-polarity voltage pulse (10ua) during a period within each of basic voltage pulses of which pulsewidth corresponds to a half cycle every half cycle of a system voltage. A power burden born by the individual single-phase inverters (5a-5c) in each half cycle is made approximately zero and the individual single-phase inverters (5a-5c) make a correction for subtracting a common voltage (Vo) from target output voltages of individual phases during the period when the reverse-polarity voltage pulse (10ua) is generated.